@Mr Khan - No offense taken, however, on a personal level, I couldn't care less what city they were played in nor what the predominant skin colour was. I care solely about the sports that I prefer and the competition.
The question isn't a matter of what event is more representative of the world, simply which one you prefer. Which one do you prefer watching?
If greater world representation enhances your viewing pleasure, and I think that that is a perfectly viable stance, then elaborate. I'm interested to hear. I'm looking at this with purely a sporting perspective.
Ideally, the two events would be seen as one sole event separated only by geography. It'd be nice if they were in the same year too, though logistically and economically it probably wouldn't make sense.
Also, I'm unsure what the demographics of these games has to do with anything - you mention mostly white, northern-hemisphere born peoples as the dominant types representing these games. I'm not sure what's wrong with that. It's simply a result of these countries interacting with their local geography. Hell, you wouldn't expect to see many Norwegian beach volleyball players. It's just simply a matter of their strengths laying elsewhere (see the Scandinavian countries - the perform much better in the Winter Olympics).